Magnetic shuttle motion



June 4, 1940. GRESNDAHL 2,203,568}

MAGNETIC SHUTTLE MOTI ON Filed Dec. 8, 193'? 3 Sheets-Sheet 1 FIG 6 4 3 1 w l l I Yip/MW INVENTOR. K 2. GroWaZQ/z/ ATTORNEYS,

5 Sheets-Sheet 2 Ill/J K. T. GRGNDAHL.

MAGNETIC SHUTTLE MOTION Filed Dec. 8, 1957 F'IGB June 4, 1940.

K QQQTXZEZ? W 044 WATTORNEYK June 4, 1940. K. T, GRESN AHL.

MAGNETIC SHUTTLE MOTION Filed Dec. 8, 1957 3 Sheets-Sheet 5 FIG? PIC-MO ATTORNEY.

Patented June 4, 1940 UNITED STATES PATENT OFFICE Application December 8, 1937, Serial No. 178,813 In Sweden December 16, 1936 4 Claims.

This invention relates to improvements in electro-magnetic shuttle motion for weaving looms with combs and oscillating shuttles.

'I'he main object of the invention is to obtain a magnetic shuttle driving motion of great speed and efliciency.

Another object of the invention is to give the shuttle motion a great security, never freeing the shuttle from the grasp of the magnetic force.

A further object of the invention is to start the shuttle with great acceleration.

A further object of the invention is to start and check the shuttle motion without vibrations of the loom.

A further object of the invention is to eliminate the drawbacks of electro-ma'gnetic shuttle driving systems as designed heretofore, and make it possible to use shuttle boxes independent of the movement of the comb.

The various attempts of magnet shuttle driving systems have failed because the devices were too complicated and expensive and their eiiiciency was poor. All influencing of the shuttle by means of intermediate magnet carriages as well gas the attaching of magnet systems to the lay of the loom have been of no practical use.

These and other drawbacks have been eliminated according to the present invention by the arrangement of electro-magnets independently of the movements of the comb, along the raceway of the shuttle, energized from an electrical source of supply to produce travelling a magnetic field directly influencing the shuttle, and means to prevent the shuttle from coming into contact with the magnets, these means being movably arranged.

. In the accompanying drawings various embodiments of the invention are illustrated more or less diagrammatically by way of example. In the drawings:

Figure l is a diagram showing the principle of the shuttle moving system with a row of driving electro-magnets in front elevation.

Fig. 2 is a front elevation of the one end of the 5 magnet row outside the end of the comb in a larger scale.

Fig. 3 is a front elevation of the magnet row in a modified arrangement and in asmall scale.

Fig. 4 is afront elevation of the one end of 50 the magnet row in thesame arrangement but in larger scale. v

Fig. 5 is a section on the line 5-5 of Fig. 2 in a larger scale.

Fig. 6 is a section on the line 6-6 of Fig. 4 in a larger scale.

Fig. 7 is a similar sectional view of the same detail as in Fig. 6 but in a modified arrangement.

Fig. 8 is a front elevation of a modified magnet and a shuttle showing also the path of a magnetic line of force.

Fig. 9 is an end view of the comb with the shuttle and the magnet at the warp threads.

Fig. 10 is a similar view to Fig. 9 but with a mradified arrangement of the comb and the magne 10 Fig. 11 is a similar view illustrating a further modified arrangement of the comb and the magnet.

Referring to the drawings, Fig. l, the driving magnets i consist of a row 2 of electro-magnets 15 preferably built up of a continuous laminated iron core along the raceway of the shuttle 3 and provided with teeth 4 directed towards the raceway, and with windings 6 around the iron core between the teeth or placed in other suitable 20 way. These teeth, hereinafter referred to as the poles of the magnets, are preferably arranged with such small spaces between them, that more than one tooth is always directly opposite the shuttle.

The windings or coils are at their ends I suecessively connected to each other, and each connecting point I is through a conductor 8 connected to a corresponding contact member 9 of a circuit breaker l0, exemplified in the form of a 30 stationary commutator with at least two brushes l2, l3, the one circumferentially spaced with respect to the other and connected to the main circuit lines l4, l5 from an electrical source of supply not shown in the drawings. The brushes, the distance between them preferably being regulable, are carried by a shaft 16 or like means, which is given an oscillating movement from the loom mechanism or in any other suitable way, so that the brushes will have an oscillating movement on the commutator, successively energizing the coils from the one end .of magnet row to the other end thereof and back again. The outer ends of the outermost coils are connected with each other by means of a conductor ll. Thus, according to this diagram three coils will be energized at the same time to provide poles of the same polarity and two additional poles will be included by movement of the brushesto establish a magnetic field travelling along the raceway of the shuttle. Naturally this is to be regarded as an example since various magnetic arrangements with suitable coil connecting systems can i be used, as well as direct or alternating currents.

In Fig. 1 the magnets are placed over the shut- 5 tie and the result thereof will be, that the shuttle will be essentially carried through the warp l1, l8 as shown in Fig. 10 and prevented by a movably arranged shield 5 from coming into contact with the magnets. The shuttle'wlll' travel in synchronism with the magnetic field. When carrying the shuttle the vertically attracting force of the magnets are so chosen that this force will essentially compensate for the weight of the shuttle with the result that the shuttle will move through the warpwith a minimum of friction.

The shuttle, being the armature of the travelling magnetic field, is near each end provided with pole-shoes I 9, 20 (see Fig. 8) of iron. connected with each other by one or more iron strips 2| preferably along the bottom of the shuttle in the vertical length middle-plane thereof as shown in Fig. 7, to provide a path for the magnetic lines of force 22. The very ends of the shuttle are preferably made of non-magnetic material for a reason mentioned below. The shield 5 forming a guide for the shuttle may also 'be of non-magnetic material.

At the ends of the shuttle raceway there are arrangements to start and brake the shuttle movement preferably combined with shuttle boxes, not shown in the drawings as immaterial for this invention. The magnet row is continued to these ends of the raceway and at the ends outside of the warp the path for the shuttle is constituted by rollers 23, see Fig. 2. These rollers, arranged in a row in the direction of the shuttle movement, are carried at a constant distance from each other by a movable holder 24, and their axles 25 can roll on and along a stationary plate 26. The holder is normally held in a positionof rest by end springs 21, 28. The movable rollers are placed in such positions, that they prevent the shuttle from coming into contact with the magnets. At the sides the shuttle is preferably guided by non-magnetic side walls 29 as shown in Fig. 5. It is also possible to place the rollers in stationary bearings.

The magnets can have difierent sectional shapes and the rollers can be arranged in one or more rows. Fig, 5 illustrates magnets with double teeth 4 and one row of rollers 23 arranged be-' tween them, and Fig. '7 shows magnets with single teeth 4 and one row of rollers 23 at each side of them, the rollers being designed in pairs, each pair with a common axle 25.

Fig. 3 illustrates amodification of the magnet row where the end magnets outside the comb are placed at the opposite side of the raceway of the shuttle with reference to the middle portion of therow. This middle portion is in the example placed over the comb 30 and the end portions of the row below the raceway. The iron core is continued along the whole row.

One of these end portions of the magnet row 2 is illustrated in Fig. 4 in combination with a driving mechanism 32 for the rollers 23. This mechanism is adapted to start and check the shuttle motion by means of the rollers in coaction with the magnetic field and is driven from the loom or in any suitable way. In order to provide that the rollers affect the shuttle with the most possible friction the magnet force should press the shuttle hard against the rollers. increase the friction a layer can be arranged between the rollers and the shuttle. For example the rollers can be provided with a rubber layer or the like. In Fig. 4, there is shown a rubber band 33 placed around the two outermost rollers of the row, these rollers working like pulleys as shownin the drawings. The driving mechanism for the rollers is preferably arranged in such a manner that the rollers accelerate and retard the shuttle movement essentially in synchronisms with the movement of the travelling magnetic field.

The roller driving mechanism can be designed when the shuttle moves insides the warp, consists of a movable shield, which prevents the shut tle from coming into contact with the magnets;

In Fig. 9 is shown an embodiment where theshield is part of the comb 30a and the upper portion thereof is bent to form a laminated roof over the shuttle and at the same time guide it. The end points'of the comb fingers are held by a rod 3|. In this and other embodiments the shuttle path has such a width that the shuttle is free to move laterally with respect to the normal longitudinal direction thereof.

The lateral movement has the form of a portion of a circle in close proximity to the magnets, the centre of the circle being situated essentially in the axis 40 of the swingable comb. In this way thecomb is prevented from affecting the shuttle, if the comb moves at the same time as the shuttle is moving through the warp, and the arrangement also has the advantage, that the shuttle can be transmitted to a path which is independent of the comb or outside the ends of the comb.

The shuttle can be guided under the warp threads, and'in Fig. 10 and Fig. 11 are shown embodiments where the shield is situated over the upper warp threads IT. The shield 5, preferably covered by felt 31, is fastened to swingable poleshoes 38 arranged betwen the poles or magnet teeth 4 and the upper warp threads H. The poleshoes andthe shield in Fig. 10 have to be periodically swung out of the way for the comb 30b by means of the loom mechanism. The pole-shoes and the shield in Fig. 11 are combined with the comb 300, so that the pole-shoes and the comb will have a common movement, and a common swing axle 39 preferably situated above the warp. The pole-shoes can be dispensed with.

The oscillating movement of the shuttle through the warp gap between the stopping points at the ends of the raceway is, as mentioned, effected by the travelling magnetic field the movements of which is controlled by the movements of the commutator brushes l2, l3. The magnet force guidingthe shuttle along the raceway prevents the same from moving out of the predetermined path. When the magnets are arranged over the warp, and the comb or other.

shield over the warp constitutes the path for the shuttle, the latter is carried through the warp without touching the warp threads or only slightly touching the same. The driving force of the magnet row will be of great efliciency, especially when the magnets are energized according to the system in Fig. 1;

In this system the two brushes of the commutator divide the current into two circuits, the one energizing a portion of the magnet row directly opposite the shuttle, and the other energizing the other portions of the magnet row with the result. that the whole iron core produces force the shuttle. The width of the path for the shuttle and also the suitable swingable movement shown in Fig. 9, makes it possible for the comb to move when the shuttle is running through the warp and without influencing the shuttle. When the shuttle approaches the end of the raceway the, shuttle engages'the rollers 23. If the rollers are driven as exemplified in Fig. 4, the rollers have a speed corresponding to the speed of the shuttle, so that the rollers receive the shuttle without shocks. In this position of the shuttle the travelling field is retarding thereby retarding the shuttle. The rollers also are given a retarding speed corresponding to the field movemerit, and as the magnetic force is urging the shuttle against the rollers, the rollers and the magnetic fields coact to continuously check the shuttle movement. The magnets attract the shuttle with such a force against the rollers, that the shuttle in passing from one roller to another would tip over between the rollers, if the very ends of the shuttle] were made of magnetic material. For this reason the ends of the shuttle are made of non-magnetic material.

When the shuttle is brought to stop, the movements of the magnetic field and of the rollers are reversed, and these movements accelerate in accordance with each other causing the shuttle to move in the reversed direction and accelerate to the desired speed. No picking motions vibrate the loom, and the coaction of the magnetic field and the rollers makes is possible to give the shuttle an enormous acceleration or retardation in a very short distance. The rollers without driving mechanism according to Fig. 2 are of corresponding use, although the magnetic field alone effects the acceleration and retardation of the shuttle. After the shuttle has been accelerated the shuttle enters the warp in the new direction, passes the warp propelled by the travelling as before, and is received by the rollers at the other end of the raceway, where it is retarded, stopped and started again in a reversed direction, and so forth.

The arrangements and designs of the magnets, the efiiciency of the energizing system, the shape of the comb, the design of the shuttle facilitating the magnetic guidance and driving, the rollers and their driving mechanism, all coact to give the whole driving system the possibility of remarkably high shuttle speed and security the shuttle along the whole raceway being forcibly guided in reference to speed and direction.

Naturally the driving system described can be combined with picking and starting devices 0 known kinds.

The magnet system also can be such that the magnets are adapted only to urge the shuttle against the rollers and to guide the shuttle through the warp. The magnet system also can be designed only as a starting and checking device for the shuttle.

It is to be understood that the invention is not limited to the arrangements hereinbefore described as it will be obvious that the construction of the elements oi! the-device may be varied in many ways to produce the desired results.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. Ina loom, a shuttle adapted for longitudinal reciprocation, a plurality of magnets and means associated therewith providing a travelling magnetic field for propelling the shuttle, said magnetsbeing arranged in a row above the reciprocating path of the shuttle and above a series of warp threads whereby the magnetic lines 01' force produced'by the magnets carry the shuttle during the propulsion thereof to counterbalance the weight of the shuttle, and a comb associated with the warp threads having teeth arranged between the magnets and the path of the shuttle providing guide means for the shuttle.

- 2. In a loom, a shuttle adapted for longitudinal reciprocation, a plurality of magnets and means associated therewith providing a travelling magnetic field for propelling the shuttle, said magnets belng arranged in a row above the reciprocating path of the shuttle and above a series of warp threads whereby the magnetic lines of force produced by the magnets carry the shuttle during the propulsion thereof to counterbalance the weight of the shuttle, a comb operatively associated with the warp threads and having teeth arranged between the magnets and the shuttle, said comb being mounted to swing in a direction transverse with respect to the longitudinal reciprocating movement of the shuttle whereby the teeth between the shuttle and the magnets prevents the shuttle from coming in contact with the magnets and the swingable comb permits lateral movement of the shuttle with respect to the magnets.

3. In a loom, a shuttle adapted for longitudinal reciprocation, a plurality of magnets and means associated therewith providing a magnetic field for guiding the shuttle, said magnets being arranged in a row above the reciprocating path of the shuttle and above a series ,of warp threads whereby the magnetic lines of force of the magnets carry the shuttle during the travel thereof to counterbalance the weight of the shuttle, and a comb associated with the warp threads having a portion of the teetharranged between the magnets aud the path of the shuttle providing guide means for the shuttle.

4. In a loom, a shuttle adapted for longitudi-- nal reciprocation, a plurality of magnets and means associated therewith providing a magnetic field for guiding the shuttle, said magnets being arranged in a row above the reciprocatingmath of the shuttle and above a series of warp threads whereby the magnetic lines of force 0! the magnets carry the shuttle during the travel thereof to counterbalance the weight of the shuttle, a comb operatively associated with the warp threads and having a portion of the teeth arranged between the magnets and the shuttle, said comb being mounted to swing in a direction transverse with respect to the longitudinal reciprocating movement or the shuttle whereby the portion of the teeth between the shuttle and the magnets prevents the shuttle from coming in contact with the magnets and the swingable comb permits lateral movement of the shuttle with respect to the magnets.

. KARL 'I'EODOR GRbNDAHL. 

